Bad breath, also called halitosis, is common and can be embarrassing. The good news is that most cases come from the mouth and can be improved with the right care.
Key points
- Most bad breath starts in the mouth, from bacteria on the tongue, between teeth and around the gums.
- Gum disease, decay, dry mouth and food trapped between teeth are common causes.
- Cleaning your tongue and between your teeth every day makes a big difference.
- Persistent bad breath despite good care should be checked.
Common causes of bad breath
- Bacteria on the tongue, especially at the back.
- Gum disease. Our guide to bleeding gums explains the signs.
- Food trapped between teeth or around old fillings and crowns.
- Dry mouth, from medicines, mouth breathing or not drinking enough. See dry mouth causes and relief.
- Decay or infection in a tooth.
- Tonsil stones. Read about tonsil stones and bad breath.
- Smoking, strong foods such as garlic and onion, and some diets.
How to freshen your breath
- Brush twice a day and gently clean your tongue with a brush or tongue scraper.
- Clean between your teeth every day.
- Drink water through the day and chew sugar-free gum to keep saliva flowing.
- Clean dentures and night guards daily, and leave dentures out overnight if advised.
- Keep up regular check-ups and cleans.
When to see us
If bad breath continues despite good home care, book a check-up. We look for gum disease, decay, leaking fillings and other causes and treat what we find. If your mouth is healthy, we may suggest seeing your GP to look at other causes. Healthdirect also has general information on bad breath.
Common questions
What is the most common cause of bad breath?
Bacteria in the mouth, especially on the back of the tongue, between teeth and around the gums. They break down food and release sulphur compounds that smell.
Does mouthwash cure bad breath?
Mouthwash can mask odour for a short time, but it does not remove the plaque and bacteria that cause it. Cleaning your teeth, gums and tongue is more effective.
When is bad breath a sign of something else?
If bad breath continues despite good cleaning and a healthy dental check, see your GP, as sinus, throat, stomach and some medical conditions can contribute.
Reviewed by the Glenmore Park Dental Services clinical team, October 2026. This article is general information, not personal dental advice.
To book, call Glenmore Park Dental Services on (02) 4733 1197 or request an appointment. We are at Shop 17b, 11 Town Terrace, Glenmore Park, and open Monday to Saturday.